Does the FRA or the commercial railroads have a hard and fast definition of what constitutes a “derailment”? My processor here used the definition “A derailment is anytime the rail wheel losses normal contact with the rail." I’ve always just accepted that and gone along with it, but now one of my activities is asking me for an authoritative reference to support it.

Also should that definition be adjusted any when you are talking about hirail equipment?

Greg

FRA Office of Safety: Guide for Preparing Accident/Incident Reports, Page 46 defines it as follows :
"Derailment. A derailment occurs when on-track equipment leaves the rail for a reason other than a collision, explosion, highway-rail crossing impact, etc."

http://safetydata.fra.dot.gov/officeofs ... efault.asp

I think in generic terms a derailment would be anytime on-track equipment leaves the rail. However, I think the definition contained in the FRA Guide is only for accident/incident classification purposes. In other words, if the equipment left the rail as a result of a collision you would classify the accident as a collision. The derailment would be secondary in that case.

Hope this helps.

Very Interesting. The Navy doesn't generally submit accident reports to the FRA (We have our own safety and accident reporting system which I suspect has a lot lower thresholds) so I've never bothered to look at this before. So an accident where a train falls off the tracks due to a collision isn't a derail.

I guess that makes sense where you are trying to develop statistics.

But it unfortunately doesn't answer question my inspector had. What I need to answer is how far off the rail does something have to move before it becomes a "derail" regardless of the ultimate cause. Most anyone would agree that if one or more wheels are on the ties, that rail car has derailed.

How about the situation where a wheel climbs a point and the car or locomotive is stopped with the flange on top of the rail?

If you have a relatively rigid 4 wheel car and rough track and you find the car stopped with one wheel with 3/8" of air between the rail head and wheel tread?

At the activity in question, all of these would currently be "derailments", and require an investigation and accident/incident report.

I need to try and come up with fair threshold so that operations don't have to be interrupted unnecessarily but hazardous conditions aren't ignored either.

Greg

I forget now what the number of the Navy Instruction is but it is the Bible for the Navy Safety Program. One volume is for ashore and the other is for afloat. At one time I could throw out instruction quotations like crazy, I was a Safety Petty Officer Afloat but that was many dead braincells ago.
The one thing about the Navy Safety Program I like is that there is no such thing as Hazardous Waste. It is all HazMat from start to destruction. Believe me when I say it is all covered in the manuals. Some cite other instructions but all is covered.

The "Bible" for Navy Trackage is NAVFAC Instruction 11230.1D (I've been trying to get the "E" revision signed for most of this year. The Navy Railway Operating Handbook is the P-301.

There are a bunch of other relevant Navy, Army and Tri-Service guidance out there, not to mention probably hundreds of local activity instructions that implement guidance from the above documents.

Unfortunately, none of Navy wide documents define a derailment. They define what to do in case of one, but what the trigger is varies from activity to activity. That is part of this exercise. To determine if I want to update one of them, and if so, how.

Greg

In that case it would come down to "What is an orange?", "What is an apple?" type of situation. You can only take it down so far without running into trouble. If you are the one making the changes call it what you want. Use the FRA rule book, the Tri-Service, or DOD definition. You know once it starts up the chain everyone will pencil whip it to death just so their mark is visible. It will come back to you in about a year nothing like the original!

Since you are making the definition for the word and the situations in which it applies for the procedures or activities being conducted, you might try the following:

Derailment (definition):

A derailment is where one or more flanged wheels on a railcar or source of motive power is no longer in contact with the railway such that the railcar or motive power is no longer being guided by the railway. Continued movement of the railcar or source of motive power after a derailment may result in damage to the railcar, its lading, the source of motive power, nearby personnel or other equipment and material.

Once you have defined "derailment" you can then use the word in the procedures to be used when derailment occurs.

Please note that the second sentence in my proposed definition is not strictly necessary for the definition. However, if you are writing procedures to be understand with a 12th grade education level, (or an 8th grade educational level), including the consequences of a derailment in the definition of a derailment would reinforce in the classroom that a derailment is a bad thing.

From someone who has written many procedures for hazardous activities.

Hope this helps.

Pkurilecz

But wheels can go on the ground and still be guided by the railway. Maybe add the words: "and/or supported by."

ie: A derailment is where one or more flanged wheels on a railcar or source of motive power is no longer in contact with the railway such that the railcar or motive power is no longer being guided by, and/or supported by the railway. Continued movement of the railcar or source of motive power after a derailment may result in damage to the railcar, its lading, the source of motive power, nearby personnel or other equipment and material.